RU2507245C2 - Cylinder lubricant for two-stroke marine engine - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: invention relates to a cylinder lubricant, having a base number (BN) determined according to standard ASTM D-2896 greater than or equal to 15 mg KOH/g of lubricant, containing: one or more lubricating base oils for marine engines, at least one detergent based on alkali or alkali-earth metals, overbased with metal carbonates, optionally in combination with one or more neutral detergents, one or more oil-soluble fatty amines containing 16-22 carbon atoms and having BN determined according to standard ASTM D-2896 from 150 to 600 mg KOH/g. The present invention also relates to use of the cylinder lubricant (versions) and an additive concentrate for preparing the cylinder lubricant.

EFFECT: obtaining a lubricant having neutralisation power with respect to sulphuric acid formed during combustion of high-sulphur liquid fuel, while limiting formation of deposits during use of low-sulphur liquid fuel.

29 cl, 4 ex, 2 tbl, 2 dwg

Description

Field of Invention

The present invention relates to a lubricant for cylinders for a two-stroke marine engine, which can be used with both high-sulfur liquid fuels and low-sulfur liquid fuels. More specifically, the invention relates to a lubricant having a sufficient neutralizing force against sulfuric acid generated during the combustion of high sulfur liquid fuel, and the formation of deposits when using low sulfur liquid fuel is limited.

State of the art

FR 2094182 describes lubricants containing a rust and corrosion inhibiting additive based on polyalkoxylated compounds including a C18 amine. A very small amount of amine is used. In addition, it is indicated that the compound used to ensure the basicity of the lubricant is carbonate.

Marine oils used in low-speed two-stroke crosshead engines are of two types. Firstly, these are cylinder oils that provide lubrication to the piston-cylinder assembly and, secondly, system oils that lubricate all moving parts except the piston-cylinder assembly. At the piston-cylinder assembly, residual combustion products containing acid gases are in contact with the lubricating oil.

Acid gases are formed as a result of the combustion of liquid fuels; in particular, they are sulfur oxides (SO ₂ , SO ₃ ), which are then hydrolyzed by contact with moisture present in the products of combustion and / or in oil. Such hydrolysis leads to the formation of sulphurous (HSO ₃ ) or sulfuric (H ₂ SO ₄ ) acid.

To protect the surface of the piston liners and in order to avoid excessive wear due to corrosion, these acids must be neutralized, which, as a rule, is carried out by interaction with the main groups that make up the lubricant.

The ability of the oil to neutralize is measured by its alkali or alkaline number characterizing its basicity. It is measured in accordance with ASTM D-2896 and expressed as the mass equivalent of potassium hydroxide per gram of oil or mg KOH / g. The alkali oil is a standard criterion that allows you to adjust the basicity of cylinder lubricating oils in accordance with the sulfur content of the liquid fuel used, in order to enable the neutralization of all sulfur contained in the liquid fuel and the ability to convert to sulfuric acid by combustion and hydrolysis.

Thus, the higher the sulfur content in liquid fuel, the higher should be the marine oil's alkaline content. Therefore, marine oils are available on the market having an alkaline oil, ranging from 5 to 100 mg KOH / g. This basicity is provided by detergents that are super-alkalized by insoluble metal salts, in particular metal carbonates. Detergents, mainly of the anionic type, are, for example, metal-containing soaps of salicylate, phenolate, sulfonate, carboxylate type, etc., which form micelles in which insoluble particles of metal salts are in suspension. Conventional super-alkaline detergents inherently have an alkaline substance, typically between 150 and 700 mg KOH per gram of detergent. Their mass percentage in the lubricant is fixed depending on the desired value of the alkali.

A certain fraction of the value of the alkaline substance can also be provided by non-super-alkalized or "neutral" detergents having an alkaline substance, typically less than 150. However, it is impossible to imagine the manufacture of a lubricant composition for the cylinders of a marine engine, where the alkaline substance is fully provided with "neutral" detergents: in fact it will be necessary to include them in excess quantities, which can degrade other properties of the lubricant and are unrealistic from an economic point of view.

Insoluble metal salts of super-alkalized detergents, such as calcium carbonate, thus make a significant contribution to the alkaline substances of conventional lubricants. It can be assumed that approximately at least 50%, typically 75% of the value of the alkaline lubricant of the lubricant for the cylinders is thus provided by these insoluble salts.

The part, which is actually a detergent, or the metal-containing soaps contained in both neutral and super-alkaline detergents, as a rule, provide most of the rest of the alkali.

Concern for the state of the environment has led in some areas, particularly in coastal regions, to requirements related to the limitation of sulfur content in liquid fuels used on ships.

So, in May 2005, Appendix 6 to the MARPOL (International Convention for the Prevention of Water Pollution from Ships) Convention, issued by IMO (International Maritime Organization), entered into force. It sets a universal limit of 4.5 wt.% For the sulfur content in heavy liquid fuels, and it also sets up zones where sulfur oxide emissions are monitored, called SECA (SOx Emission Control Areas). Ships entering these areas are required to use liquid fuels with a maximum sulfur content of 1.5 wt.% Or any other alternative treatment designed to limit emissions of SOx (sulfur oxides) in order to meet these emission requirements. The value in wt.% Denotes the mass content of the compound in percent relative to the total mass of liquid fuel or lubricating composition in which it is located.

Later, the Marine Environment Protection Committee (MEPC), at a meeting in April 2008, approved the proposed changes to MARPOL Annex 6. These suggestions are summarized in the table below. They reflect the scenario in which the restriction of the maximum sulfur content becomes more stringent, and the total maximum sulfur content common to the whole world should decrease from 4.5 wt.% To 3.5 wt.% From 2012. SECA (Sulfur Oxide Emission Control Areas) will become Emission Control Areas (ECA). In these zones, the maximum permissible sulfur content since 2010 has been reduced from 1.5 wt.% To 1.0 wt.% And new restrictions have been introduced on the content of nitrogen oxides (MOx) and particles.

Applicable rules in accordance with MARPOL Annex 6 Maximum sulfur content General limit SECA limit 4.50 wt.% 1.50 wt.% Amendments to MARPOL Annex 6 (MEPC meeting No. 57, April 2008) Maximum sulfur content General limit Limit for ECA zones 3.5 wt.% To 1.01.2012 1 wt.% To 01.03.2010 0.5 wt.% To 1.01.2020 0.1 wt.% To 01.01.2015

Ships crossing transcontinental routes already use several types of heavy liquid fuels depending on local environmental restrictions, while being able to optimize their operating costs. The situation will remain the same, whatever the final level of maximum sulfur content allowed in liquid fuels.

This condition is established for most container ships that are currently designed for the use of several fuel tanks - for liquid fuels for the high seas with a high sulfur content and for liquid fuels for use in SECA zones with a sulfur content of not more than 1.5 wt.% .

The transition from one of the two indicated categories of liquid fuel to one of these may require the adaptation of engine operating conditions, in particular the use of appropriate lubricants for the cylinders.

Currently, in the presence of liquid fuels with a high sulfur content (3.5 wt.% And more), marine lubricants are used, having an alkali oil of about 70.

In the presence of liquid fuels with a low sulfur content (1.5 wt.% Or less), marine lubricants with an alkali oil of about 40 are used (this value should be reduced in the future).

In both of these cases, a sufficient neutralizing ability is achieved, since the necessary concentration of the main groups is ensured due to the super-alkaline detergents of the marine lubricant, but it is necessary to change the lubricant every time when changing the type of liquid fuel.

In addition, each of these lubricants has limitations on use resulting from the following observations:

the use of a lubricant for cylinders with a rating of 70 in the presence of liquid fuel with a low sulfur content (1.5 wt.% or less) and a fixed level of lubrication lead to a significant excess of the main groups (high alkaline) and the risk of destabilization of unused super-alkaline detergent micelles, which contain insoluble metal salts. Such destabilization results in the formation of deposits of insoluble metal salts having a high degree of hardness (for example, calcium carbonate), mainly in the area above the piston ring, and can lead to the risk of excessive wear by the type of polishing of the piston sleeve over a long period.

Thus, the optimization of the lubrication of the cylinders of a low-speed two-stroke engine requires the choice of a lubricant with an alkali oil suitable for liquid fuel and the engine operating mode. Such optimization reduces the operational flexibility of the engine and requires significant technical skills on the part of the crew to determine the conditions under which one type of lubricant must be replaced by another.

Thus, to simplify operations, it may be desirable to have a single cylinder lubricant for a two-stroke marine engine that can be used with high sulfur liquid fuel and low sulfur liquid fuel.

In particular, there is a need for compositions in which the alkali is not provided with super-alkaline detergents, but with compounds that do not lead to the formation of metal deposits when they are present in excess with respect to sulfuric acid, which needs to be neutralized.

Description of the invention

An object of the present invention is to provide a lubricating oil that can provide good lubrication to the cylinder of a marine engine and can also satisfy the limitations of high sulfur liquid fuels and the limitations of low sulfur liquid fuels.

The present invention relates to lubricating compositions having a high enough alkali in order to effectively neutralize the sulfuric acid generated when using liquid fuel with a high sulfur content, where a significant part of the specified alkali is provided by oil-soluble particles, which do not lead to the formation of metal deposits when partially consumed. in case of using low-sulfur liquid fuel.

Thus, the present invention relates to a cylinder lubricant having an alkali oil defined in accordance with ASTM D-2896, greater than or equal to 15, preferably greater than or equal to 20, preferably greater than or equal to 30, most preferably greater than or equal to 40 milligrams potassium hydroxide per gram of lubricant containing:

- one or more basic lubricating oil for marine engines,

- at least one detergent based on alkali or alkaline earth metals, super-alkaline with metal carbonates, possibly in combination with one or more than one neutral detergent,

- one or more oil-soluble fatty amines and / or derivatives of fatty amines having an alkaline substance, defined in accordance with ASTM D-2896, comprising from 150 to 600 milligrams of potassium hydroxide per gram, preferably from 200 to 500 milligrams of potassium hydroxide per gram,

moreover, the mass percentage of fatty amines and / or their derivatives relative to the total mass of the lubricant is chosen so that the contribution of the alkali provided by these compounds to the total alkali of the specified lubricant for cylinders is at least 10 milligrams of potassium hydroxide per gram of lubricant, preferably at least 20 milligrams of potassium hydroxide per gram, preferably at least 30 milligrams of potassium hydroxide per gram, even more preferably at least 40 milligrams of potassium hydroxide a gram of lubricant, and

the mass content in percent of super-alkalized detergents relative to the total mass of the lubricant is chosen so that the contribution of alkali provided by metal carbonates to the total alkali of the specified lubricant for cylinders is at most 20 milligrams of potassium hydroxide per gram of lubricant.

The Applicant has found that it is possible to create a lubricant composition for cylinders in which a significant part of the alkali oil is provided by oil-soluble fatty amines, while maintaining a level of product quality comparable to standard compositions with an equivalent alkali oil.

The required characteristics in particular are the ability to neutralize sulfuric acid, which is measured using the enthalpy test described in the examples below.

Nevertheless, it is impossible to completely eliminate the contribution to the alkali that is caused by insoluble metal particles of super-alkaline detergents: they constitute the “last reserve” of mandatory basicity when used with high-sulfur liquid fuel (for example, more than 3 wt.%, Or even 3.5 wt.% )

In addition, these insoluble metal salts have a favorable anti-wear effect if they are maintained dispersed in the lubricant in the form of stable micelles.

In addition, it was found that the inclusion of too high an amine content leads to a significant decrease in the viscosity of the lubricant, so that it practically ceases to be suitable for use as a lubricant for cylinders. In addition, this may have an adverse effect on the toxicity of said lubricant.

The applicant also unexpectedly found that if there is a significant contribution to the value of alkali from the indicated fatty amines, too much contribution to the alkali (more than 20 mg of potassium hydroxide per gram of lubricant) is from the side of insoluble ultra-alkaline detergents with metals (usually metal carbonates) , has an adverse effect on the neutralizing ability of the lubricant for the cylinders.

In standard lubricants for cylinders with an average value of 40, the composition of which is selected for use with low-sulfur liquid fuels, the average value provided by insoluble metal salts is usually about 30 mg potassium hydroxide per gram of lubricant.

Due to the alternative contribution to alkali, which is provided by fatty amines that do not form hard metal deposits, leading to wear of parts, in combination with super-alkaline and possibly neutral detergents, cylinder lubricants in accordance with the present invention are suitable for high-sulfur liquid fuels and low-sulfur liquid fuel.

In one embodiment of the invention, the alternative contribution to alkali provided by the oil-soluble fatty amines is at least 15%, preferably at least 30%, preferably at least 50%, of the alkaline lubricant for said cylinder lubricant. Or even, in particular, in the case of compositions having an alkalinity of about 55, the alkali provided by the oil-soluble fatty amines is at least 55%, or at least 60%, or at least 70% of the alkali oil of said cylinder lubricant.

Preferably, the present invention provides cylinder oil having an alkali oil defined in accordance with ASTM D-2896, comprising 40 to 80 milligrams of potassium hydroxide per gram of lubricant, preferably 65 to 75, or more preferably 70 milligrams of potassium hydroxide per gram of lubricant.

According to another embodiment, the alkali oil lubricant according to the present invention, determined in accordance with ASTM D-2896, is from 45 to 60 milligrams of potassium hydroxide per gram of lubricant, preferably from 45 to 55, or more preferably equal to 50 milligrams of hydroxide potassium per gram of lubricant.

According to yet another embodiment, the alkaline lubricant of the lubricant according to the present invention, determined in accordance with ASTM D-2896, is from 54 to 60 milligrams of potassium hydroxide per gram of lubricant, preferably it is 57, or also preferably 55 milligrams of potassium hydroxide per gram of lubricant.

According to yet another embodiment, the alkaline lubricant of the lubricant according to the present invention, determined in accordance with ASTM D-2896, is from 40 to 50 milligrams of potassium hydroxide per gram of lubricant, preferably equal to 45 milligrams of potassium hydroxide per gram of lubricant.

In accordance with one embodiment, for reasons of cost and availability, the oil-soluble (s) fatty (s) amine (s) and derivatives thereof are derived from palm, olive, peanuts, oilseed rape, oilseed rape, sunflower oil, soybean or cottonseed oil, from beef tallow, or from palmitic, stearic, oleic or linoleic acid.

In accordance with one embodiment, the fatty amines are selected from amines derived from fatty acids containing from 16 to 18 carbon atoms.

In order to avoid the phenomenon of gelation, which is found at a high mass content of fatty amines in the lubricant, it is preferable to use fatty amines containing from 12 to 24 carbon atoms, preferably from 16 to 22 carbon atoms.

In accordance with one embodiment, the fatty amines are mono- or polyamines, preferably diamines, and the derivatives of the fatty amine are mono- or polyamine derivatives, preferably diamine derivatives.

In a preferred embodiment, they are polyamines of the general formula R- [NH (CH ₂ ) ₃ ] n-NH ₂ where n is an integer of 1 to 3 and R is a fatty chain of saturated or unsaturated fatty acids containing at least 16 carbon atoms, preferably oleic acid fatty chain, and fatty amine derivatives are derivatives of the same diamines.

Derivatives of the fatty amine according to the present invention are, for example, derivatives of the amines described above. These derivatives, for example, are selected from ethoxylated amines having from 1 to 5 ethylene oxide moieties and oxyamines.

In the lubricants of the present invention, the super-alkaline and / or neutral detergents are preferably selected from carboxylates, sulfonates, salicylates, naphthenates, phenolates and mixed detergents, which are combinations of at least two of these types of detergents.

Preferably, they are compounds based on metals selected from the group consisting of calcium, magnesium, sodium or barium, preferably calcium or magnesium.

They are co-alkaline due to insoluble metal salts selected from the group of carbonates of alkali and alkaline earth metals, preferably calcium carbonate.

These detergents provide additional alkali, which is not provided by oil-soluble fatty amines and their derivatives in cylinder oils in accordance with the invention.

According to a preferred embodiment, the mass content of super-alkaline detergents as a percentage of the total weight of the lubricant is selected such that the alkali provided by the metal carbonates contributes at least 5 milligrams of potassium hydroxide per gram of lubricant, preferably at least 10 milligrams of hydroxide potassium per gram of lubricant into the total value of the alkaline substance of the specified lubricant for cylinders.

According to a particularly preferred embodiment, the mass content of super-alkaline and possibly neutral detergents as a percentage of the total mass of the lubricant is selected so that in the lubricant for the cylinders of the present invention, the contribution of organic alkali provided by the metal-containing soap detergents is at least 5 milligrams of potassium hydroxide per gram of lubricant, preferably at least 10 milligrams of potassium hydroxide per gram of lubricant society.

Preferably, the lubricant according to the present invention contains from 50 to 90 wt.% Base oil, from 4 to 30 wt.% At least one detergent based on alkali or alkaline earth metals, super alkali metal carbonates, possibly in combination with one or more one neutral detergent, and from 2 to 40 wt.% one or more fatty amines and / or derivatives of fatty amines, as described above.

Lubricants in accordance with the invention may contain one or more functional additives selected from a dispersing agent, antiwear additives, anti-foam additives, antioxidants and / or anti-corrosion additives.

For example, they may contain from 0.01 wt.% To 6 wt.%, Preferably from 0.1 wt.% To 4 wt.% Of one or more than one antiwear additives.

They may also contain from 0.1 wt.% To 4 wt.%, Preferably from 0.4 wt.% To 2 wt.% Of a dispersing agent.

The cylinder lubricants according to the invention preferably have a kinematic viscosity at 100 ° C. of 12.5 to 26.1 cSt (grade SAE 40, 50, 60), preferably of 16.3 to 21.9 cSt (grade 50) .

According to a particularly preferred embodiment, the lubricants for the cylinders of the invention have a kinematic viscosity at 100 ° C. of 18 to 21.5 cSt, preferably 19 to 21.5 cSt.

Preferably, the lubricants for the cylinders of the invention contain from 60% to 90% based on the total weight of the lubricant, a mixture of one or more base oils belonging to Groups 1-5 according to the American Petroleum Institute nomenclature, preferably Groups 1 or 2 according to the same nomenclature.

This base oil mixture may contain from 10 to 25 wt.% Of the total mass of the lubricant of the BSS Group I base oil lubricant (distillation residue having a kinematic viscosity at 100 ° C. of approximately 30 mm ² / s, typically from 28 to 32 mm ² / s, and with a density at 15 ° C ranging from 895 to 915 kg / m ³ ), and 50-70 wt.% Of the total weight of the lubricant of the Group I base oil, which is solvent neutral (Solvent Neutral ) type, (distillation product, with a density at 15 ° C, component from 880 to 900 kg / m ³ , with a kinematic viscosity at 100 ° C approximately 11 mm ² / s for SN 500, or approximately 12 mm ² / s for SN 600).

According to yet another embodiment in cylinder oils in accordance with the invention, the base oil (s) has been partially or completely replaced (s) by one or more than one thickening agent and / or IV improving (viscosity index) polymers.

Another objective of the invention relates to the use of the lubricant described above, as the only lubricant for cylinders, which can be used with any type of liquid fuel, the sulfur content of which is less than 4.5%; preferably, the sulfur content in the specified liquid fuel is from 0.5 to 4 wt.%.

Preferably, the same cylinder lubricant according to the invention can be used both with liquid fuel with a sulfur content of less than 1.5 wt.%, And with liquid fuel with a sulfur content of more than 3 wt.%, Or even more than 3.5 wt.%.

According to a preferred embodiment, the same cylinder lubricant according to the invention can be used both with liquid fuel with a sulfur content of less than 1 wt.%, And with liquid fuel with a sulfur content of more than 3 wt.%.

Another objective of the invention relates to the use of the lubricant described above to prevent corrosion and / or reduce the formation of deposits of insoluble metal salts in two-stroke marine engines during the combustion of any type of liquid fuel, the sulfur content of which is less than 4.5 wt.% .

In accordance with another objective, the invention relates to the use of one or more compounds selected from oil-soluble fatty amines and their derivatives, for example fatty amines and their derivatives described above, to provide an alternative alkali, without the formation of any solid metal deposits in lubricants for cylinders for two-stroke marine diesel engines having an alkali motor, measured in accordance with ASTM D-2896, greater than or equal to 15, preferably more than 20, preferably more than 30, most respectfully more than 40 milligrams of potassium hydroxide per gram of lubricant.

Another objective of the invention relates to a method for the manufacture of a lubricant described above, in which the fatty (s) amine (s) and / or its derivatives thereof are added as separate components of a lubricant for cylinders having a base fluid defined in accordance with the standard ASTM D-2896 greater than or equal to 15, preferably more than 20, preferably more than 30, most preferably more than 40 milligrams of potassium hydroxide per gram of lubricant, which optionally includes one or more than one functional additive.

In accordance with one embodiment, a lubricant is prepared by dissolving one or more additive concentrates for marine lubricants, which includes (s) the fatty (s) amine (s) and / or its derivatives.

In accordance with another objective of the invention relates to a concentrate of additives for the manufacture of lubricants for cylinders having an alkali oil, defined in accordance with ASTM D-2896, greater than or equal to 15, preferably more than 20, preferably more than 30, most preferably more than 40 milligrams of hydroxide per gram of lubricant, where the specified concentrate has an alkaline substance, comprising from 250 to 300, and contains one or more fatty amines and / or a derivative of a fatty amine having an alkaline alkali, comprising from 150 to 600 mg of potassium hydroxide I / g amine in accordance with ASTM D-2896, where the mass percentage of these fatty amines and / or derivatives in the concentrate is selected so as to obtain the specified concentrate with a contribution to the alkali, determined in accordance with ASTM D-2896, constituting from 35 to 270 milligrams of potassium hydroxide per gram of concentrate.

DETAILED DESCRIPTION OF THE INVENTION

Fatty amines and their derivatives as an alternative to the alkaline detergents source of alkali:

The fatty amines used in the lubricants of the present invention are primary, secondary or tertiary monoamines or polyamines containing one or more aliphatic chains, or derivatives thereof.

These compounds have their own basicity, which makes it possible to use them as an important source of alkaline substances in lubricants for cylinders, as a substitute for detergents, in particular super-alkaline detergents. The intrinsic alkali fatty amines and derivatives used in the present invention, measured in accordance with ASTM D-2896, are typically 150 to 600 milligrams of potassium hydroxide per gram, preferably 200 to 500 milligrams of potassium hydroxide per gram.

They are cationic surfactants, the polar head of which consists of a nitrogen atom (and possibly one or more oxygen atoms in the case of derivatives of the oxyamine type and ethoxylated amines), and the lipophilic part consists of the aliphatic (s) chain (s) thereof.

Fatty amines are mainly derived from carboxylic acids. These acids are dehydrated in the presence of ammonia to give nitriles, which are then subjected to catalytic hydrogenation to give primary, secondary or tertiary amines.

The starting fatty acids for the preparation of fatty amines are, for example, caprylic, pelargonic, capric, undecylenic, lauric, tridecylenic, myristic, pentadecylinic, palmitic, margarine, stearic, nonacenuicuinoicuanoicanuicanoicanuicanoicanuicanoicanuicanoicanuicanosuinoicanuicanoicanuicanoicanuicanoicanuicanoicanuino , montanoic, nonacosanoic, melissic, gentriacontanoic or lacaric acid or unsaturated fatty acids such as palmitoleic, oleic, erucic, aceteruco hydrochloric acid, linoleic, α-linolenic, c-linolenic, di-homo-c-linolenic, arachidonic, eicosapentenic or docosahexanoic acid.

Preferred fatty acids are obtained by hydrolysis of triglycerides present in vegetable and animal oils, such as copra, palm, olive, peanut, rapeseed, sunflower, soybean, cottonseed or linseed oil, beef tallow, etc .; natural oils can be genetically modified to increase the content of certain fatty acids, for example, oleic, rapeseed or sunflower oil.

The fatty amines that are used in the lubricants of the invention are preferably obtained from natural plant or animal sources. Processing to produce fatty amines from natural oils can result in the formation of mixtures of primary, secondary and tertiary monoamines and polyamines.

In the lubricants in accordance with the present invention, for example, products containing in varying proportions all or some of the compounds corresponding to the following formulas may be included:

RNH2,

R-NH-R

R-NHCH2-R

R- [NH (CH ₂ ) ₃ ] ₂ -NH ₂

R- [NH (CH ₂ ) ₃ ] ₂ -NH ₂

where n is an integer greater than or equal to 1, and R is a fatty chain derived from the fatty acid (s) present (s) in the original oil. The same fatty monoamines or polyamines may also contain several fatty chains derived from various fatty acids.

These products can also be used in purified form containing mainly one type of amine, for example mainly diamines.

Thus, it is preferable to use a product consisting of diamines having the formula R- [NH (CH ₂ ) ₃ ] ₂ -NH ₂ , where R may be a plurality of fatty acids originating from a natural source, for example beef fat.

Refined products can also be used. For example, it is preferable to use amines derived from oleic acid, in particular diamines having the formula R- [NH (CH ₂ ) ₃ ] ₂ -NH ₂ , where R is the oleic acid fatty chain.

The amines in accordance with the present invention are soluble in the oil matrix, which facilitates their inclusion in the lubricant, and due to this, these amines are able to more easily reach drops of neutralizable acid dispersed in said oil matrix in order to be more effective. Thus, the fatty amines in the lubricant in accordance with the present invention are not in the form of an emulsion or microemulsion, but are well dispersed in an oil matrix.

Therefore, the fatty amines in accordance with the present invention preferably include at least one alisratic chain consisting of at least 16 carbon atoms, preferably at least 18 carbon atoms.

In order to avoid gelation, which sometimes occurs at high mass contents of fatty amines in a lubricant, fatty amines containing from 12 to 24 carbon atoms, preferably from 16 to 22 carbon atoms, are particularly preferred.

The alkali amines of the amines in accordance with the invention are between 150 and 600, and the minimum number of alkali alkali provided by these amines is 10 milligrams of potassium hydroxide per gram of lubricant, which allows them to be used in a lubricant with a minimum content of about 2 wt.%. Nevertheless, this content can be increased in a standard way to values of the order of 20 wt.%, For example, providing 40 or more units of alkali with an amine with alkali 200.

Derivatives of fatty amines:

In the lubricants of the present invention, an alternative to hyper alkalized detergents of alkali can be provided by derivatives of fatty amines. These derivatives are, for example, ethoxylated amines obtained by condensation of ethylene oxide with primary or secondary amines, amine oxides obtained by the reaction of tertiary fatty amines with hydrogen peroxide, or quaternary ammonium salts synthesized from tertiary amines.

Alkaline lubricant according to the present invention

The alkaline lubricants of the lubricants according to the present invention are provided with neutral or super alkaline detergents based on alkali or alkaline earth metals and one or more fatty amines and / or their derivatives.

The value of this alkali, measured in accordance with ASTM D-2896, can be from 5 to 100 mg KOH / g or higher. A lubricant with a fixed value of alkali oil is selected depending on the conditions of use of the specified lubricant, in particular in accordance with the sulfur content in the liquid fuel used and in connection with lubricants for the cylinders.

The lubricants in accordance with the present invention are suitable for use as lubricants for cylinders, regardless of the sulfur content of the liquid fuel used as fuel in the engine.

Thus, the lubricants for cylinders for two-stroke marine engines in accordance with the invention have an alkalinity greater than or equal to 15, preferably more than 20, preferably more than 30, more preferably more than 40, preferably from 40 to 80.

In accordance with a preferred embodiment of the invention, the lubricating composition has a value of alkali, measured in accordance with ASTM D-2896, suitable for use with high sulfur liquid fuels having a sulfur content of 4.5 wt.%, That is, alkali oil is from 65 to 75, or even equal to 70.

In accordance with another embodiment, the alkali oil lubricant according to the present invention is from 45 to 60, preferably from 45 to 55, or even equal to 50.

In accordance with one embodiment, the alkali oil lubricant according to the present invention is from 55 to 60, or even equal to 57, or even equal to 55.

In the lubricants of the present invention, the contribution to alkali provided by fatty amines and derivatives is at least 10 units, preferably at least 20 units, preferably at least 30 units, even more preferably at least 40 units. The contribution to the alkali, provided by the fatty amine in the lubricant (in milligrams of potassium hydroxide per gram of final lubricant, or “units” of alkali), is calculated based on its own alkali, impregnated in accordance with ASTM D-2896, and its mass content in percent in the finished lubricant:

Amino _{amine lubricant} = x. Amino _amine / 100

ЩЧ _{amine lubricant.} = Amine contribution to alkali in the finished lubricant

x =% by weight of amine in the finished lubricant

Alkaline _amine = intrinsic alkaline of the amine itself (ASTM D 28-96).

Thus, in the case of a lubricant with alkali oil 70 according to the present invention, fatty amines and derivatives provide a minimum of 14% alkali oil. In the case of a lubricant with alkalis 55 according to the present invention, fatty amines and derivatives provide a minimum of 18% alkalis. In the case of a lubricant with alkali oil 40 according to the present invention, fatty amines and derivatives provide a minimum of 25% alkali oil.

Since these fatty amines and their derivatives themselves have an alkali content of 100 to 600, preferably 200 to 400, the mass percentage of these compounds in the lubricants according to the present invention is more than 1.7% (10 units of alkaline matter are provided by an amine with an alkaline substance of 600 ), as a rule, more than 2%.

Fatty amines, however, do not provide the whole alkali in the lubricants of the present invention. The applicant has found that the inclusion of high-fatty amines leads to a significant decrease in viscosity, and therefore, when exceeding the maximum percentage of fatty amines, it is impossible to obtain a lubricant having the viscosity coefficient required when used as a lubricant for cylinders, unless extremely large quantities of thickeners, which would lead to unrealistic from an economic point of view of the compositions and would degrade other properties of the lubricant.

The inclusion of high amines can also lead to toxicity problems.

In order to prepare lubricants suitable for high and low sulfur contents, they typically work with alkaline alkalis of the order of 55 or 57, or 70, where at least 10 alkaline alkaline agents are provided with super-alkaline detergents. Thus, as a maximum, 60 units of alkaline matter usually provide fatty amines, which corresponds to the maximum mass content in percentage of fatty amines of the order of 10, 15, 30, or 40% for amines with alkaline alkali 600, 400, 200 or 150, respectively.

Unexpectedly, the applicant also found that only lubricants in which both amines and super-alkalized detergents contribute to the alkali oil, show satisfactory neutralizing efficacy (i.e., of the order of 100 or more), up to the maximum alkaline level provided by metal carbonates of super-alkalized detergents.

Without wishing to be limited by any theory, the applicant believes that these metal carbonates, which constitute the last reserve of basicity for use as a lubricant for cylinders with a high sulfur content, had a slower kinetics of neutralization of sulfuric acid in comparison with metal-containing soaps and amines.

Thus, the contribution to alkali provided by metal carbonates originating from super-alkalized detergents in the lubricants of the present invention is at most 20 units (20 milligrams of potassium hydroxide per gram of lubricant). This contribution to the alkali, hereinafter referred to as "carbonate alkali" or "CaCO ₃ , alkali" is measured in accordance with the method described in Example 1 below.

The composition of conventional oils having an alkali oil of greater than or equal to 40 in accordance with the invention is thus changed by replacing fatty amines with super-alkaline detergents so that they provide at least 10 alkali lubricant units, preferably at least 30 alkali alkali lubricant, which makes it possible to adequately prevent corrosion problems when using high sulfur liquid fuel (about 4, 5 wt.%).

This also makes it possible to reduce the formation of precipitation of insoluble metal salts, providing super-alkalization (for example, CaCO ₃ ), in the case of using low-sulfur liquid fuel (1.5 wt.% Or less). This decrease, directly related to the decrease in the content of super-alkaline detergents, was made possible due to the structure of the composition in accordance with the present invention.

Thus, the lubricants according to the present invention, in particular with alkali oil constituting from 65 to 75, for example alkali oil 70, can be used with high-sulfur and low-sulfur liquid fuels.

Super Alkaline or Super Alkaline Detergents

Detergents used in lubricating compositions in accordance with the present invention are well known to specialists in this field of technology.

Detergents commonly used in the manufacture of lubricating compositions are typically anionic compounds containing a long lipophilic hydrocarbon chain and a hydrophilic head. The associated cation is typically an alkali or alkaline earth metal cation.

The detergents are preferably selected from salts of an alkali or alkaline earth metal and carboxylic acid, sulfonates, salicylates, naphthenates, as well as phenolates.

The alkali and alkaline earth metals are preferably calcium, magnesium, sodium or barium.

These metal salts may contain metal in approximately stoichiometric amounts. In this case, detergents are referred to as “non-super-alkalized” or “neutral”, although they do provide some basicity. These "neutral" detergents typically have an alkaline substance, measured in accordance with ASTM D2896, less than 150 mg KOH / g or less than 100 mg, or even less than 80 mg KOH / g.

This type of so-called neutral detergent can partially contribute to the alkaline lubricant in accordance with the present invention. For example, neutral detergents are used, such as carboxylates, sulfonates, salicylates, phenolates, naphthenates of alkali and alkaline earth metals, for example calcium, sodium, magnesium or barium.

When the metal is present in excess (in an amount greater than the stoichiometric amount), we are talking about the so-called super-alkaline detergents. Their alkalinity is high, greater than 150 mg KOH / g, and typically ranges from 200 to 700 mg KOH / g, typically from 250 to 450 mg KOH / g.

The excess metal, providing the super-alkaline nature of the detergent, is presented in the form of metal salts that are insoluble in fuel, for example carbonate, hydroxide, oxalate, acetate, glutamate, preferably carbonate.

In the same super-alkaline detergent, the metals of these insoluble salts may be the same or different from the metals of oil-soluble detergents. They are preferably selected from calcium, magnesium, sodium or barium.

Super-alkalized detergents are thus presented in the form of micelles, consisting of insoluble metal salts, supported by detergents in suspension in a lubricating composition in the form of oil-soluble metal salts.

These micelles may contain one or more types of insoluble metal salts stabilized by one or more types of detergents.

Super-alkaline detergents containing one type of soluble metal salt with a detergent, as a rule, get names in accordance with the nature of the hydrophobic chain of the specified detergent.

Thus, they are considered to be of the phenolate, salicylate, sulfonate or naphthenate type depending on whether this detergent is, respectively, phenolate, salicylate, sulfonate or naphthenate.

Super-alkaline detergents are considered to be of the mixed type if micelles contain several types of detergents that differ from each other in the nature of their hydrophobic chain.

For use in the lubricating compositions of the present invention, the oil-soluble metal salts are preferably phenolates, sulfonates, salicylates and mixed phenolates — sulfonate detergents and / or salicylates of calcium, magnesium, sodium or barium.

The insoluble metal salts, which are extremely alkaline in nature, are alkali and alkaline earth metal carbonates, preferably calcium carbonate.

Super-alkalized detergents used in the lubricating compositions of the present invention are preferably phenolates, sulfonates, salicylates and mixed phenolates - sulfonate - salicylate detergents, Super-alkali calcium carbonate.

The alkali provided by detergents. in lubricants according to the invention:

In the lubricants according to the present invention, part of the alkali metal oxide is provided with insoluble metal salts and super-alkaline detergents, in particular metal carbonates.

Thus, the mass content of super-alkalized detergents in percent relative to the total mass of the lubricant is chosen so that the contribution to the total alkaline alkali of the specified lubricant for the alkaline number cylinders provided by metal carbonates is at most 20 milligrams of potassium hydroxide per gram of lubricant.

The alkali provided by metal carbonates is measured separately for the super-alkaline detergent and / or in the finished lubricant in accordance with the method described in Example 1. Typically, in the ultra-alkaline detergent, alkali provided by the metal carbonates is from 50 to 95% of the total alkali of the super-alkaline detergent separately.

These insoluble metal salts also have a favorable anti-wear effect if they are maintained dispersed in a lubricant in the form of stable micelles, which does not occur when they are present in excess relative to the amount of sulfuric acid that must be neutralized during operation.

Thus, in accordance with a preferred embodiment of the invention, insoluble metal salts with super-alkaline detergents provide at least 5 milligrams of potassium hydroxide per gram of lubricant (or 5 “alkali units”) in the lubricants of the present invention, preferably at least 10 alkali units.

In addition, the present detergents, which are metal-containing soaps of a substantially phenolate or salicylate or sulfonate type, also contribute to the alkaline lubricants of the lubricants of the present invention. This contribution to alkaline alkali, hereinafter referred to as “organic alkaline alkali,” comes from both neutral and super alkalized detergents.

These metal-containing soaps, for their part, have a positive effect on the behavior of cylinder lubricants under thermal loads. Thus, it is preferable that some of the alkaline lubricants of the lubricants according to the present invention are provided with said metal-containing soaps.

According to a preferred embodiment in the cylinder lubricants of the present invention, organic alkaline alkali provided by metal-containing soaps contributes at least 5 milligrams of potassium hydroxide per gram of lubricant, preferably at least 10 milligrams of potassium hydroxide per gram of lubricant .

Thus, the alkali oil lubricant according to the present invention, measured in accordance with ASTM D289, includes at least 3 separate components:

- The alkali content provided by fatty amines, defined as a function of alkaline amines, measured in accordance with ASTM 2896, and the mass percentage of fatty amines.

- alkaline alkali, provided by insoluble metal salts with super-alkaline detergents, called in the broad sense "carbonate alkali" or "CaCO ₃ alkali", and measured using the method described in Example 1 below.

- An “organic” alkali, provided by metal-containing soaps of super-alkaline and possibly neutral detergents, obtained as the difference between the total alkali of the lubricant and other contributing components.

Base oils

In general, the base oils used for the manufacture of lubricants in accordance with the present invention may be mineral, synthetic, or vegetable oils, as well as mixtures thereof.

Mineral or synthetic oils, mainly used according to this application, belong to one of the classes defined in the API classification, as summarized in the table below.

Saturated Content Sulfur content Viscosity index Group 1 Mineral Oils <90% > 0.03% 80≤IV <120 Group 2 Hydrocracked Oils ≥90% ≤0.03% 80≤IV <120 Group 3 Hydroisomerized Oils ≥90% ≤0.03% ≥120 Group 4 PAO (polyalphaolefin) Group 5 Other grounds not included in the main groups 1-4

Mineral oils in Group 1 can be obtained by distillation of the selected naphthenic or paraffinic crude oil, then by purification of these distillation products using methods such as solvent extraction, solvent dewaxing or catalytic dewaxing, hydroprocessing or hydrogenation.

The oils in Groups 2 and 3 were obtained using more difficult refining methods, for example, by a combination of hydroprocessing, hydrocracking, hydrogenation and catalytic dewaxing.

Examples of synthetic bases in Groups 4 and 5 include polyalpha-olefins, polybutylenes, polyisobutylenes and alkylbenzenes.

These base oils can be used individually or in a mixture. Mineral oil can be combined with synthetic oil.

Cylinder oils for two-stroke marine diesel engines have a viscosity grade of SAE-40 to SAE-60 (classification of the Association of Automotive Engineers - Society of Automotive Engineers), typically SAE-50 is equivalent to a kinematic viscosity at 100 ° C of 16.3 to 21 , 9 mm ² / s.

Grade 40 oils have a kinematic viscosity at 100 ° C of 12.5 to 16.3 cSt.

50 grade oils have a kinematic viscosity at 100 ° C of 16.3 to 21.9 cSt.

Grade 60 oils have a kinematic viscosity at 100 ° C of 21.9 to 26.1 cSt.

In accordance with industrial practice, it is preferable to obtain compositions of cylinder oils for two-stroke marine diesel engines having a kinematic viscosity at 100 ° C of 18 to 21.5, preferably from 19 to 21.5 mm ² / s (cSt).

This viscosity can be obtained using a mixture of additives and base oils, for example, containing Group 1 mineral bases, such as solvent neutral bases (e.g. SN 500 or SN 600), and highly viscous residual cylinder oil. You can use any other combination of mineral or synthetic bases, or bases of plant origin, having in a mixture with additives a viscosity compatible with class SAE 50.

Typically, the standard cylinder lubricant composition for low speed two-stroke marine diesel engines is SAE 40 - SAE 60, preferably SAE 50 (according to SAE J300 classification) and includes at least 50 wt.% Lubricant base oil of mineral and / or synthetic origin suitable for use in marine engines, for example, belonging to API Class 1, i.e. obtained by distillation of selected crude oil, then purification of these distillation products using such methods such as solvent extraction, solvent dewaxing or catalytic dewaxing, hydroprocessing or hydrogenation. Their viscosity index (VI) ranges from 80 to 120; their sulfur content is more than 0.03% and their content of saturated components is less than 90%.

Typically, the standard cylinder lubricant composition for low-speed marine two-stroke diesel engines comprises 18–25 wt.% Based on the total mass of the BSS Group I base oil lubricant (distillation residue having a kinematic viscosity at 100 ° C of approximately 30 mm ² / s, usually from 28 to 32 mm ² / s, and with a density at 15 ° C of 895 to 915 kg / m ³ ), and 50-60 wt.% relative to the total mass of the lubricant of Group I of the base oil of type SN 600 (distillation product with a density at 15 ° C of about 880 to 900 kg / ^m3 and a kinematic viscosity at 100 ° C of about 12 ^mm2 / s).

Thickeners:

The applicant has shown that the incorporation of significant amounts of fatty amines (typically of the order of 5-15 wt.%, Or more than 10 wt.%, Or even of the order of 20 wt.%) Into the lubricants of the present invention has the effect of decreasing the viscosity of the lubricant. Thus, it may be necessary, in particular in the case of a higher amine content, to introduce into the lubricants according to the present invention thickening and / or viscosity index improving polymers having an action increasing the viscosity of the lubricant. This makes it possible to obtain lubricants for cylinders having a viscosity grade suitable for their use.

Thus, in accordance with one embodiment in the lubricants for the cylinders of the present invention, the base oil (s) is partially or completely replaced with one or more thickening additives, the role of which is to increase the viscosity of the composition in the warm and cold state, or viscosity index improvers (VI).

These additives are most often low molecular weight polymers of the order of 2000-50000 Daltons (MM).

They can be selected from polyisobutylene (about 2,000 Daltons), polyacrylate or polymethacrylates (about 30,000 Daltons), olefin copolymers, olefin and alpha-olefin copolymers, ethylene-propylene monodiene, polybutenes, high molecular weight polyalphaolefins (viscosity at 150 ° C or more) styrene-olefin copolymers, hydrogenated or non-hydrogenated.

In the cylinder lubricants of the present invention, the polymers used to partially or completely replace one or more of the base oils are preferably the aforementioned thickeners such as polyisobutylene (for example, marketed under the name Indopol H2100).

They are preferably present in an amount of 5-20 wt.% In the lubricants for the cylinders according to the invention, preferably from 8 to 20% in the case of an amine content of more than 15 wt.%.

Antiwear additives:

The lubricants according to the present invention contain, with an equivalent alkali oil, a smaller amount of super-alkaline detergents compared to those in standard cylinder lubricants. Thus, the lubricant for cylinders with alkali oil 70 typically contains about 25 wt.% Super-alkaline detergents, whereas in the lubricants according to the invention with alkali oil 70 this content can be reduced to about 15% or even less than 5%.

As mentioned above, these compounds may have a positive antiwear effect. Therefore, the lubricants for the cylinders according to the invention preferably contain anti-wear additives.

Antiwear additives protect friction surfaces by forming a protective film adsorbed on these surfaces. Zinc dithiophosphate or DTPZn is most commonly used. Various phosphorus, sulfur, nitrogen, chlorine and boron compounds are also in this category.

There is a wide variety of antiwear additives, but the most commonly used category is the category of phosphorus and sulfur containing additives, such as metal alkylthiophosphates, in particular zinc alkylthiophosphates, and more particularly zinc dialkyldithiophosphates or DTPZn. Preferred compounds have the formula (Zn ((SP (S) (OR1) (OR ₂ )) ₂ , where R1 and R2 are alkyl groups, preferably containing 1-18 carbon atoms. DTPZn is typically present in an amount of the order of from 0.1 up to 2 wt.%.

Aminphosphates and polysulfides, in particular sulfur-containing olefins, are also commonly used antiwear additives.

Nitrogen and sulfur containing type antiwear additives and extreme pressure additives, such as, for example, metal dithiocarbamates, in particular molybdenum dithiocarbamates, are also commonly present in lubricating compositions. Glycerol esters are also antiwear additives. For example, mention may be made of mono-, di- and trioleates, monopalmitates and monomyristates.

Antiwear additives and extreme pressure additives are presented in lubricant compositions in an amount of 0.01 to 6%, preferably 0.1 to 4%.

According to a preferred embodiment, the lubricants for the cylinders of the present invention comprise at least 0.5% by weight of one or more antiwear additives.

Preferred antiwear additives are of the type DTPZn.

Dispersing Agents

Dispersing agents are well known additives used in the preparation of lubricating compositions, in particular for use in the marine field. Their main role is to maintain in suspension particles that are initially present or appear in the lubricant composition during its use in the engine. They prevent their agglomeration by acting on steric barriers. They may also have a synergistic effect on neutralization.

Dispersing agents used as additives in lubricants typically contain a polar group bonded to a relatively long hydrocarbon chain, typically containing 50-400 carbon atoms. The polar group typically contains at least one nitrogen, oxygen or phosphorus.

Compounds derived from succinic acid are dispersing agents, in particular used as additives in lubricants. In particular, succinimides obtained by condensation of succinic anhydrides and amines are used, and succinic acid esters obtained by condensation of succinic anhydrides and alcohols, or polyols.

These compounds can then be treated with various compounds, in particular sulfur, oxygen, formaldehyde, carboxylic acids and compounds containing boron or zinc, to obtain, for example, boron succinimides or zinc-blocked succinimides.

Mannich bases obtained by polycondensation of phenols substituted with alkyl groups, formaldehyde and primary or secondary amines are also compounds used as dispersants in lubricants.

In accordance with one embodiment of the present invention, at least 0.1% of a dispersing agent is used. A dispersing agent of the polyisobutylene succinimide family, for example, boron or zinc blocked, may be used.

Other functional additives

The lubricant composition in accordance with the present invention may also contain any functional additives suitable for use, for example, antifoam additives that compensate for the effect of detergent detergents, which can be, for example, polar polymers such as polymethylsiloxanes, polyacrylates, antioxidants and / or anti-corrosion additives, for example, organometallic detergents or thiadiazoles. The latter are known to those skilled in the art. These additives are usually contained in an amount of from 0.1 to 5 wt.%.

In accordance with the present invention, the described compositions of lubricants relate to compounds taken separately before mixing, it should be understood that these compounds may or may not retain the same chemical form before and after mixing. Preferably, the lubricants of the present invention obtained by mixing the compounds taken separately are not in the form of an emulsion or microemulsion.

Additive concentrations for marine lubricants:

The fatty amines and derivatives contained in the lubricants of the present invention may in particular be included in the lubricant as separate additives. However, the fatty amines and derivatives contained in the lubricants of the present invention may also be included in a marine lubricant additive concentrate.

Standard concentrates of additives for marine lubricants for cylinders, as a rule, consist of a mixture of the above components, detergents, dispersants, other functional additives, base oils before dilution, in proportions that make it possible to obtain lubricants for cylinders with alkali oil after dilution in the base oil defined in accordance with ASTM D-2896, greater than or equal to 15, preferably more than 20, preferably more than 30, most preferably more than 40 milligrams of calcium hydroxide I per gram of lubricant. This mixture typically contains a detergent with a content relative to the total weight of the concentrate greater than 80%, preferably greater than 90%, the content of dispersing agent is from 2 to 15%, preferably from 5 to 10%, the content of other functional additives is from 0 to 5%, preferably from 0.1 to 1%. The alkali of these concentrates, measured in accordance with ASTM D 2896, typically ranges from 250 to 300 milligrams of potassium hydroxide per gram of concentrate, typically about 275 milligrams of potassium hydroxide per gram of concentrate.

In accordance with one object, the invention relates to a concentrate of additives for the manufacture of cylinder lubricants having an alkali oil, defined in accordance with ASTM, greater than or equal to 15, preferably more than 20, preferably more than 30, more preferably more than 40 milligrams of potassium hydroxide per gram of lubricant, where the specified concentrate has an alkaline substance, constituting from 250 to 300, and contains one or more fatty amines and / or derivatives of a fatty amine with alkaline substances, constituting from 150 to 600 mg of sodium hydroxide / g of amine, respectively in accordance with ASTM D-2896, where the percentage by weight of these fatty amines and / or derivatives in the concentrate is selected so as to obtain the indicated concentrate giving an alkaline contribution, determined in accordance with ASTM D-2896, from 35 (14 % from 250) to 270 (90% of 300) milligrams of potassium hydroxide per gram of concentrate.

According to yet another embodiment, the percentage by weight of said fatty amines and / or derivatives in the concentrate is selected so as to obtain said concentrate giving an alkali contribution, determined in accordance with ASTM D-2896, from 60 (25% to 250 ) and 225 (75% of 300) milligrams of potassium hydroxide per gram of concentrate.

According to yet another embodiment, the percentage by weight of said fatty amines and / or derivatives in the concentrate is selected so as to obtain said concentrate giving an alkali contribution, determined in accordance with ASTM D-2896, from 135 (55% of 250 ) up to 225 (75% of 300) milligrams of potassium hydroxide per gram of concentrate.

Fatty amines in concentrates according to the invention as an alternative to the detergent source of alkaline substances are as described above and in the following examples.

The concentrates in accordance with the invention also contain a certain amount of base oil, small but sufficient to facilitate the use of these additive concentrates.

Measurement of differences in performance between a conventional comparative lubricant and a lubricant according to the invention

This measurement is characterized by a neutralization efficiency index, measured in accordance with the enthalpy test method, described in detail in the examples in which the exothermic neutralization reaction is monitored by increasing temperature, which is detected when said lubricant containing basic groups is brought into contact with sulfur acid.

Of course, the present invention is not limited to the described and presented examples and embodiments, but there may be numerous variations available to a person skilled in the art.

Examples:

Example 1: this example is intended to describe a method for measuring the contribution of insoluble metal salts present in super-alkaline detergents to alkaline lubricating compositions containing said super-alkaline detergents:

The measurement of the total basicity (the so-called alkaline or alkaline number) of the finished lubricating oils or super-alkaline detergents is carried out using the ASTM method D2896. The alkali is composed of two different forms:

- carbonate alkaline, provided by super-alkalization of the detergent with metal carbonates, such as calcium carbonate, hereinafter referred to as "alkaline",

- the so-called organic alkali, provided by a metal-containing soap of a detergent, essentially a phenolate type or a type of salicylate or sulfonate ester.

Carbonate alkali, hereinafter referred to as "alkali _CaCO3 ", is measured in the final oil or in individual super-alkaline detergents in accordance with the following procedure. It is based on the principle of attack of carbonate (calcium), a highly alkaline sample, with sulfuric acid. This carbonate is converted to carbon dioxide in accordance with the reaction;

Since the reactor volume is constant, the pressure increases in proportion to the release of CO ₂ .

Method: in a 100 ml reaction vessel equipped with a lid on which a differential pressure gauge is mounted, the necessary quantity of product is weighed, whose ЩЧСаСО3 should be measured so as not to exceed the measurement limit of the differential pressure gauge, which corresponds to an increase in pressure of 600 mb. The amount is determined according to the graph in FIG. 2, indicating for each mass of the product (from 1 to 10 grams, from right to left in the FIG) the pressure measured on a differential pressure gauge (which corresponds to an increase in pressure due to the release of CO ₂ ) depending on the proportion of alkaline particles in the sample. If the value of ShchChSaCO _{3 is} unknown, then a small amount of product is hung up, approximately 4 g. In all cases, the sample weight (m) is indicated.

The reaction vessel may be made of pyrex, glass, polycarbonate, etc. or any other material that promotes heat exchange with the environment, so that the internal temperature of the vessel quickly reaches equilibrium with the ambient temperature.

A small amount of SN 600 liquid base oil is introduced into a reaction vessel containing a small magnetic stirrer.

Approximately 2 ml of concentrated sulfuric acid is placed in the reaction vessel, being careful not to mix the medium at this stage.

The plug and the pressure gauge assembly are screwed onto the reaction vessel. Thread may be lubricated. They are tightened to ensure complete closure.

Mixing is carried out, which is continued for as long as necessary to stabilize the pressure and to achieve equilibrium of temperature with the environment. A period of 30 minutes is sufficient. The increase in pressure P and the ambient temperature T ° C (st) are recorded.

The assembly is cleaned with a heptane type solvent.

Calculation Method

To calculate the pressure, the ideal gas formula is used.

PV = nRT

P = Partial pressure of CO ₂ (Pa) (1 Pa = 10 ^-2 mb)

V = Container volume (m ³ ).

P = 8.32 (J).

T = 273 + σ (° C) = (° K).

n = number of moles of released CO ₂

$$\mathrm{<figure-callout\; id="2"\; label="P\; C\; O"\; filenames="00000010.png"\; state="\{\{state\}\}">P\; </figure-callout>}C{O}_{}{}_2=\frac{\mathrm{<figure-callout\; id="2"\; label="n\; C\; O"\; filenames="00000010.png"\; state="\{\{state\}\}">n\; </figure-callout>}C{O}_{}{}_2*R*T}{V}*{10}^{-2}$$

Calculation of the amount of mole of CO ₂ .

m * thyroid carbonate = mg KOH equivalent.

m = mass of product in grams

Alkali carbonate = alkali expressed in KOH per 1 g equivalent.

высвобождающегося CO₂, т.е. количество моль высвобождающегося CO₂: $$\frac{m*UH\mathrm{to}\mathrm{but}Rb\mathrm{about}n\mathrm{but}t\mathrm{but}\frac{44}{2*56.1}}{1000}=g$$

released CO ₂ , i.e. the number of moles of released CO ₂ :

$$\frac{m*UH\mathrm{to}\mathrm{but}Rb\mathrm{about}n\mathrm{but}t\mathrm{but}*44*{10}^{-3}}{44*2*56.1}=m*UH\mathrm{to}\mathrm{but}Rb\mathrm{about}n\mathrm{but}t\mathrm{but}*0.0089{10}^{-3}$$

Formula for calculating CO pressure? depending on alkali carbonate.

$$R\mathrm{FROM}{\mathrm{ABOUT}}_2=\frac{m*UH\mathrm{to}\mathrm{but}Rb\mathrm{about}n\mathrm{but}t\mathrm{but}*0.0089{10}^{-3}*R*T*{10}^{-2}}{V}$$

Formula for calculating alkali carbonate based on CO ₂ pressure

$$UH\mathrm{to}\mathrm{but}Rb\mathrm{about}n\mathrm{but}t\mathrm{but}=\frac{R*V}{m*0.0089*{10}^{-3}*R*T*{10}^{-2}}$$

By fixing those values that are related to the testing conditions, they get a simplified formula:

PCO ₂ = value read on the differential pressure gauge, in mbar = registered P

V = container volume in m ³ = 0.0001.

R = 8.32 (J).

T = 273 + σ (° C) = (° K). σ = recorded ambient temperature.

m = mass of product introduced into the reaction vessel.

$$UH\mathrm{to}\mathrm{but}Rb\mathrm{about}n\mathrm{but}t\mathrm{but}=\frac{RReg\mathrm{and}\mathrm{from}tR\mathrm{and}R\mathrm{about}\mathrm{at}\mathrm{but}nn\mathrm{about}e*0.0001}{m*0.0089*{10}^{-3}*8.32*(273*\sigma read)*{10}^{-2}}$$

$$UH\mathrm{to}\mathrm{but}Rb\mathrm{about}n\mathrm{but}t\mathrm{but}=\frac{RReg\mathrm{and}\mathrm{from}tR\mathrm{and}R\mathrm{about}\mathrm{at}\mathrm{but}nn\mathrm{about}e}{m*0.0074*R*(273*\sigma read)}$$

The result obtained is an alkali _CaCO3 expressed in mg KOH / g.

The alkalinity provided by the metal-containing soaps of detergents, also called "organic alkalis," is calculated as the difference between the total alkalis in accordance with ASTM D2896 and the alkali _CaCO3 thus measured.

Example 2: this example is used to describe the enthalpy test, which makes it possible to measure the neutralizing effectiveness of lubricants against sulfuric acid.

The presence or availability of the main groups included in the lubricant, in particular in the lubricant for the cylinders for a two-stroke marine engine with respect to acid molecules, can be quantified using a dynamic test of speed control or neutralization kinetics.

Principle:

The acid-base neutralization reactions are usually exothermic and it is therefore possible to measure the heat output resulting from the reaction of sulfuric acid in the lubricants that are tested. This release is observed by increasing temperature for a long time in an adiabatic reactor such as a dewar vessel.

Based on these measurements, it is possible to calculate an index that quantifies the effectiveness of the lubricant according to the present invention compared to the lubricant used as a comparative, and represents a fixed number of alkali units that need to be neutralized for a particular added amount of acid. The alkali of the test lubricant is preferably redundant with respect to the alkali, which is necessary in order to neutralize the added amount of acid. In order to test lubricants with an alkaline substance 70 in the following examples, an amount of acid corresponding to the neutralization of 55 alkaline substances is added.

Thus, the performance index is calculated relative to the comparative oil, which is assigned a value of 100. It is the ratio of the neutralization reaction time for the comparative (S _cf. ) and the measured sample (S _meas ):

Index of neutralizing efficiency = S _cf. / S _meas. × 100

The magnitudes of this neutralization reaction time, which are of the order of several seconds, are determined from the temperature increase curves as a function of time during the neutralization reaction (see the curve in FIG. 1).

The duration S is equal to the difference t _f -t _i honey time at a temperature at the end of the reaction and time at a temperature at the beginning of the reaction.

The time t _i at the temperature at the beginning of the reaction corresponds to the first temperature increase after the start of mixing.

The time t _f at the temperature at the end of the reaction is the time from which the temperature signal remains stable for a period of time greater than or equal to half the reaction time.

A lubricant is most effective when it provides a short neutralization time and therefore a high index.

Used equipment:

The geometry of the reactor and the mixer, as well as the operating conditions, are chosen so that they are within the chemical range, where the effect of diffusion restrictions in the oil phase is negligible.

Thus, in the equipment configuration used, the depth of the liquid layer should be equal to the inner diameter of the reactor, and the screw mixer should be located approximately 1/3 up from the liquid level.

The equipment consists of an adiabatic reactor with a volume of 300 ml of a cylindrical type with an internal diameter of 52 mm and an internal height of 185 mm, with a stirring rod equipped with a screw with oblique blades, 22 mm in diameter; the diameter of the blades is from 0.3 to 0.5 with respect to the diameter of the Dewar vessel, i.e. from 15.6 to 26 mm.

The position of the screw is fixed at a distance of approximately 15 mm from the base of the reactor. The mixing system is driven by a motor with a varying speed from 10 to 5000 rpm and is equipped with a temperature recording system depending on time.

This system is suitable for measuring the reaction time from about 5 to about 20 seconds and for measuring a temperature increase of several tens of degrees, starting at a temperature of about 20 ° C-35 ° C, preferably about 30 ° C. The position of the temperature registration system in the Dewar vessel is fixed.

The mixing system is controlled so that the reaction occurs in the chemical range: in the configuration of the equipment according to the present invention, the rotation speed is regulated at 2000 rpm, and the position of the system is fixed.

In addition, the chemical range of the reaction also depends on the level of oil placed in the Dewar vessel, which should be equal to the diameter of the flask, and which corresponds in the context of this experiment to the mass of the test substance of approximately 86 g.

In order to test lubricants with alkalis 70, the amount of acid corresponding to the neutralization of 55 units of alkalis is placed in the reactor.

4.13 g of 95% concentrated sulfuric acid and 85.6 g of the test lubricant are placed in the reactor in the case of a lubricant with an alkali oil 70.

After the mixing system is placed inside the reactor so that the acid and the lubricant mix well and reproducibly in two tests, stirring is started to observe the reaction in the chemical range. The data reading system is permanent.

Enthalpy Test Implementation - Calibration:

In order to calculate the performance indices of the lubricants in accordance with the present invention using the method described above, the inventors chose, as a comparative, the neutralization reaction time measured for cylinder oil for a two-stroke marine engine with SHCH 70 (measured in accordance with ASTM D-2896), not containing fatty amines in accordance with the present invention.

This oil is obtained from a mineral base obtained by mixing a distillation product having a density at 15 ° C of 880 to 900 kg / m ³ with a residue after distillation having a density of 895 to 915 kg / m ³ (high viscosity residual cylinder oil) with a distillation product / residue ratio of 3.

To this base is added a concentrate containing super-alkalized calcium sulfonate with an alkaline substance, equal to 400 mg KOH / g, a dispersing agent and super-alkaline calcium phenolate with an alkali, equal to 250 mg KOH / g. This oil is prepared in a special way in order to achieve a neutralizing ability sufficient for use with liquid fuels having a high sulfur content, namely an S content of more than 3% or even 3.5%.

The comparative lubricant contains 25.50% by weight of this concentrate. Its alkali base, equal to 70, is provided exclusively by super-alkaline detergents (super-alkaline phenolates and sulfonates) contained in this concentrate.

This comparative lubricant has a viscosity at 100 ° C. of 18 to 21.5 mm ³ / s.

The neutralization reaction time of this oil (hereinafter comparative Href) is 10.59 seconds, and its neutralizing effectiveness index is fixed at a value of 100.

Example 3: in this example, it is described by comparing the influence of the alkali contribution provided by metal carbonates on the performance of cylinder oils, namely their neutralizing effectiveness.

In this example, several cylinder oils A, B, C with 70 ShchCh are used, in which a part of ShchCh is provided, as well as in comparative oil, due to the concentrate of super-alkaline detergents, and the other part is provided by a mixture of fatty polyamines derived from beef fat containing mainly palmitic, stearic and butyric acids. This amine mixture has an alkaline base of 460 mg KOH / g. It consists of compounds having the formula K [NH- (CH ₂ ) ₃ ] _n NH ₂ , where R is a fatty chain of palmitic, stearic or butyric acids, and n is an integer of 0 to 3.

The comparative oil is a two-stroke marine engine cylinder oil 70 for the two-stroke marine engine, named in the previous example Href.

Table 1 further summarizes all the characteristics of the comparative oil and test samples, as well as all values of their performance indices.

Table 1 H ref A B C % by weight of the composition Super Alkalized Phenolate Concentrate + Sulfonates 25,50 21.30 17.10 12.90 Fatty (poly) amines, alkaline 460 mg KOH / g, ASTM D2896 0.00 2,50 5.00 7.50 Group 1 base oils 74.50 76,20 77.90 79.60 The properties KB 100 (kinematic viscosity) (cSt), ASTM D445 20.5 19.21 18.36 16.51 KB 40 (cSt), ASTM D445 243.7 221.1 208.3 178 Total alkalinity (mg KOH / g, ASTM D-2896) 70.1 71 69,4 73,4 From it, alkali provided by fatty amines (mg KOH / g, ASTM D-2896) 0 (0% SHCHCH) 11.50 (16%) 23 (33%) 34.50 (47%) From it, the alkali provided by CaCO ₃ (mg KOH / g) 51.0 (74% Shp) 42.6 (60%) 34.2 (49%) 25.8 (35%) Neutralizing Effectiveness Index (IE) one hundred 59 65 76

It should be noted that the index of the neutralizing efficiency of lubricants is significantly less than 100, when the contribution of alkali provided by metal carbonates is more than 20 milligrams of potassium hydroxide per gram of lubricant.

Example 4: this example in accordance with the invention describes the effect of the contribution made to alkali metal carbonates on the parameters of cylinder oils, namely on neutralizing efficiency.

The comparative oil is a marine oil with a schЧch 70 for a two-stroke marine engine, named in Example 1 Href.

Oils G to J contain, as an alternative source of alkaline alkali sweeteners for super alkalized detergents, a compound containing mainly a fatty diamine derived from oleic acid having the formula RNH (CH ₂ ) ₃ NH ₂ where R is an oleic acid fatty chain. The alkali content of this compound is 320 mg KOH / g (Dinoram O).

Oils K and L contain, as an alternative source of alkaline alkaline alkali peroxide for super alkalized detergents, a compound containing mainly a fatty C 16 amine of the type dimethyl-hexadecyl-amine. The alkali content of this compound is 200 mg KOH / g (Genamine 16R).

The fatty amines in this example provide about 40 alkali units out of a total of 70, i.e. approximately 57%. The remaining alkaline matter is provided by detergents such as neutral phenolate, super-alkaline phenolate and super-alkaline sulfonate.

It should be noted that the index of neutralizing effectiveness of lubricants is more than 100 in the case when the contribution to the value of alkali metal carbonates is less than 20 milligrams of potassium hydroxide per gram of lubricant.

In addition, to compensate for the decrease in viscosity caused by the introduction of fatty amines, and to obtain lubricants that satisfy the requirements for use as cylinder oil for a two-stroke marine diesel engine, polyisobutylene is added to the composition.

In addition, it should be noted that the G oil exhibits a moderate anti-wear effect (as measured, for example, in the ASTM D2670 test carried out in an apparatus with a rod and V-shaped blocks FALEX) in comparison with the comparative Href. Thus, attempts have been made to compensate for this decrease in anti-wear performance by adding an anti-wear additive such as DTPZn to H, I, J, K, and L.

This decrease in performance is likely due to a decrease in the content of super-alkaline detergents, which in the form of stable micelles have a positive anti-wear effect (on the contrary, if the micelles are destabilized, for example, when super-alkaline detergents are in excess with respect to the amount of acid produced during operation, the formation of hard metal deposits that cause wear).

The characteristics and performance of the oils thus obtained are summarized in Table 2. Oils H, I, J, and K are preferred oils of the invention having an efficiency index comparable to or even greater than that of a comparative oil, and viscosity allows their use as a lubricant for cylinders.

H ref G H I J K L % by weight of the composition Super alkali phenolates and / or sulfonates 25,50 4.00 4.00 4.00 11.00 4.00 4.00 Neutral Phenolates 9.00 9.00 9.00 9.00 9.00 Fatty diamines of oleic acid, alkali 320 mg KOH / g, ASTM D2896 12.50 12.50 12.50 12.50 Genamine 16 R ALP 200 mg KOH / g, ASTM D2896 20.00 20.00 Group 1 base oils 74.50 73.45 72.95 65.00 66.00 50.55 57.50 Polyisobutylene Indopol H2100 7.95 8.95 14.90 7.95 DTPZn 0.50 0.50 0.50 0.50 0.50 Dispersing agent 1.05 1.05 1.05 1.05 1.05 1.05 The properties KB 100 (cSt), ASTM D445 20.52 21.89 21.47 19.56 20.16 19.83 13.40 KB 40 (cSt), ASTM D445 243.7 250,4 251 197.29 202.50 165.54 99.80 Total alkalinity (mg KOH / g, ASTM D-2896.) 70.1 70 71 72 70 70 69.6 From it ShchCh, 0 (0% 40 39.7 39.7 39.7 39.8 39.8 provided by fatty amines (mg KOH / g, ASTM D-2896) ЩЧ) (57%) (56%) (57%) (57%) (57%) (57%) From it, the alkali provided by CaCO ₃ (mg KOH / g) 51.0 (74% Shp) 16.9 (24%) 16.9 (24%) 16.9 (23%) 16.0 (23%) 16.9 (24%) 16.9 (24%) Index of neutralizing effectiveness (FM) one hundred 114 120 117 104 101 118 table 2

Claims (29)

1. A cylinder lubricant having an alkaline base (alkaline number), determined in accordance with ASTM D-2896, greater than or equal to 15 mg potassium hydroxide per gram of lubricant, containing:
a) one or more lubricating base oils for marine engines,
b) at least one detergent based on alkali or alkaline earth metals, super-alkaline with metal carbonates, possibly in combination with one or more neutral detergents,
c) one or more oil-soluble fatty amines containing from 16 to 22 carbon atoms and having an alkaline substance, defined in accordance with ASTM D-2896, comprising from 150 to 600 mg of potassium hydroxide per gram,
moreover, the mass percentage of fatty amines relative to the total mass of the lubricant is selected so that the contribution of alkali provided by these compounds to the total alkali of the specified lubricant for cylinders is at least 10 mg of potassium hydroxide per gram of lubricant, and
the mass percentage of super-alkalized detergents relative to the total mass of the lubricant is chosen so that the contribution of alkali provided by metal carbonates to the total alkali of the specified lubricant for cylinders is at most 20 mg potassium hydroxide per gram of lubricant. 2. A cylinder lubricant according to claim 1, wherein the oil-soluble fatty amines have an alkaline substance, defined in accordance with ASTM D-2896, comprising from 200 to 500 mg of potassium hydroxide per gram. 3. The cylinder lubricant according to claim 1, in which the mass percentage of fatty amines relative to the total mass of the lubricant is selected so that the contribution of alkali provided by these compounds to the total alkaline alkali of said cylinder lubricant is at least 30 mg potassium hydroxide per gram of lubricant. 4. The lubricant for cylinders according to claim 1, in which the mass percentage of fatty amines relative to the total mass of the lubricant is selected so that the alkaline substance provided by these compounds is at least 15% alkaline alkaline lubricant for the cylinder. 5. The cylinder lubricant according to claim 1, in which the mass percentage of fatty amines relative to the total weight of the lubricant is selected so that the alkali provided by these compounds is at least 30% of the alkaline cylinder lubricant. 6. The cylinder lubricant according to claim 1, in which the mass percentage of fatty amines relative to the total mass of the lubricant is selected so that the alkali provided by these compounds is at least 50% of the alkaline cylinder lubricant. 7. A lubricant for cylinders according to any one of claims 1 or 2, having an alkaline substance, defined in accordance with ASTM D-2896, comprising between 40 and 80 mg of potassium hydroxide per gram of lubricant. 8. A cylinder lubricant according to claim 1, wherein the oil-soluble fatty amine (s) are obtained from palm, olive, peanuts, oilseed rape, oilseed rape, sunflower oil, soy or cottonseed oil, beef oil fat, or from palmitic, stearic, oleic or linoleic acid. 9. The cylinder lubricant according to claim 1, wherein the oil-soluble (e) fatty (e) amine (s) are derived from fatty acids containing from 16 to 18 carbon atoms. 10. The cylinder lubricant according to claim 1, wherein the fatty amines are polyamines corresponding to the general formula R- [NH (CH ₂ ) ₃ ] _n —NH ₂ , where n is an integer from 1 to 3 and R is a fatty chain of saturated or unsaturated fatty acids containing at least 16 carbon atoms. 11. The cylinder lubricant of claim 10, wherein R is an oleic acid fatty chain. 12. A cylinder lubricant according to claim 1, wherein the fatty amines are diamines corresponding to the general formula R-NH- (CH ₂ ) ₃ -NH ₂ , where R is a saturated or unsaturated fatty acid fatty chain containing at least at least 16 carbon atoms. 13. A cylinder lubricant according to claim 12, wherein R is an oleic acid fatty chain. 14. The cylinder lubricant according to claim 1, wherein the super alkali and / or neutral detergents are selected from carboxylates, sulfonates, salicylates, naphthenates, phenates, and mixed detergents containing a combination of at least two of these types of detergents. 15. The cylinder lubricant according to claim 1, wherein the super-alkali and / or neutral detergents are compounds based on metals selected from the group consisting of calcium, magnesium, sodium, or barium. 16. A cylinder lubricant according to Claim 15, wherein the super alkali and / or neutral detergents are compounds based on metals selected from the group consisting of calcium, magnesium. 17. A lubricant for cylinders according to claim 1, in which the super-alkaline detergents are super-alkaline with insoluble metal salts selected from the group of carbonates of alkali and alkaline earth metals. 18. The cylinder lubricant according to claim 1, in which the mass percentage of super-alkaline detergents relative to the total mass of the lubricant is selected so that the contribution of alkali provided by metal carbonates to the total alkaline alkali of said cylinder lubricant is at least 5 mg potassium hydroxide per gram of lubricant. 19. A cylinder lubricant according to claim 18, wherein the mass percentage of super-alkaline detergents relative to the total weight of the lubricant is selected so that the contribution of alkali provided by metal carbonates to the total alkaline alkali of said cylinder lubricant is at least 10 mg potassium hydroxide per gram of lubricant. 20. The cylinder lubricant according to claim 1, in which the mass percentage of super-alkaline and possibly neutral detergents relative to the total mass of the lubricant is selected so that the contribution of organic alkali provided by the metal-containing detergent soaps to the cylinder lubricants in accordance with this the invention was at least 5 mg potassium hydroxide per gram of lubricant. 21. The cylinder lubricant according to claim 20, in which the mass percentage of super-alkaline and possibly neutral detergents relative to the total mass of the lubricant is selected so that the contribution of organic alkali provided by the metal-containing detergent soaps in the cylinder lubricants in accordance with this the invention was at least 10 mg potassium hydroxide per gram of lubricant. 22. A lubricant for cylinders according to claim 1, characterized in that its kinematic viscosity, measured in accordance with ASTM D445 at 100 ° C, is from 12.5 to 26.1 cSt. 23. A lubricant for cylinders according to item 22, wherein its kinematic viscosity, measured in accordance with ASTM D445 at 100 ° C, is from 16.3 to 21.9 cSt. 24. A lubricant for cylinders according to claim 1, in which one or more of the base oil is partially or completely substituted by one or more polymers, which are thickeners and / or improve the viscosity index (VI). 25. The use of a lubricant for cylinders according to any one of claims 1 to 24 as the only lubricant for cylinders that can be used with liquid fuel having a sulfur content of less than 1.5 wt.%, And with liquid fuel having a content of sulfur more than 3.5 wt.%. 26. The use of a lubricant for cylinders according to any one of claims 1 to 24 as the only lubricant for cylinders that can be used with liquid fuel having a sulfur content of less than 1 wt.%, And with liquid fuel having a sulfur content of more than 3 wt.%. 27. The use of a lubricant according to any one of claims 1 to 24 for preventing corrosion in two-stroke marine engines during the combustion of any type of liquid fuel, the sulfur content of which is less than 4.5 wt.%. 28. The use of a lubricant according to any one of claims 1 to 24 to reduce the formation of insoluble deposits of metal salts in two-stroke marine engines during the combustion of any type of liquid fuel, the sulfur content of which is less than 4.5 wt.%. 29. A concentrate of additives for the preparation of a lubricant for cylinders having an alkaline substance, determined in accordance with ASTM D-2896, greater than or equal to 15 mg of potassium hydroxide per gram of lubricant, where the specified concentrate has an alkaline substance, ranging from 250 to 300, and contains one or more fatty amines with an alkali content of 150 to 600 mg potassium hydroxide / g amine in accordance with ASTM D-2896, where the percentage by weight of these fatty amines in the concentrate is selected so as to ensure the contribution of the alkaline alkali of the specified concentrate a, determined in accordance with ASTM D-2896, comprising from 35 to 270 mg of potassium hydroxide per gram of concentrate.

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